Rescue workers are seen at the wreckage of a commuter train that derailed on Dec 1, 2013 in the Bronx. (Photo TIMOTHY CLARY/AFP/Getty Images)

NEW YORK (CBSNewYork/AP) — The MTA has increased its use of plainclothes “spotters” who slip on board unnoticed to observe co-workers. The stepped-up effort comes two weeks after a deadly Metro-North train derailment.

The move also comes a year after a special on-board unit with the same task was disbanded amid scandal after auditors found workers failed to do the job.

Federal and state officials have focused on the train’s engineer, William Rockefeller, whose lawyer said may have been in a daze. The train was going 82 mph as it entered a 30 mph turn and ran off the track near the Spuyten Duyvil station, investigators said.

MTA Adds Undercover 'Spotters' After Derailment

But federal authorities say they are now taking a close look at Metro-North’s safety systems overall.

The Federal Railroad Administration said Thursday it is launching a comprehensive safety assessment of the entire Metro-North Railroad.

The two-month effort, which beings Monday, will assess a broad range of practices, including oversight of engineers, fatigue management programs and medical requirements for crew members.

“This in-depth investigation will help ensure that Metro-North is doing everything possible to improve its safety record,” U.S. Department of Transportation Secretary Anthony Foxx said.

Connecticut’s Transportation Commissioner Jim Redeker said the two-month assessment offers a format for workers themselves to speak candidly about their observations.

“For people in the field ,if they see something, they can report it confidentially,” he told WCBS 880’s Connecticut Bureau Chief Fran Schneidau.

Metro-North spokesman Adam Lisberg said the railroad is “always happy to work with anyone who has good ideas about how to keep our customers and our employees safe.”